non-SCSI disks on a SCSI disk interface (was Re: Space, the next frontier) - test-drb@ccmp.vtda.org

26 May 1999

OMTI (SMS) and ADAPTEC made quite a few of these SCSI-HOST to MFM or RLL
devices.  It seems to me that NOVELL capitalized on this proliferation of
these bridge controllers as well, providing a configuration utility for use
with their SCSI board.  I don't know how well they worked, but I imagine
they had "little" problems with them as did nearly everyone else.

Has anyone ever used a SCSI-hosted bride controller of this sort with
essentially no problems at all?  If so, I'd surely like to know which one
and how it was implemented.

Dick

-----Original Message-----
From: Frank McConnell &lt;fmc(a)reanimators.org&gt;
To: Discussion re-collecting of classic computers
&lt;classiccmp(a)u.washington.edu&gt;
Date: Wednesday, May 26, 1999 3:58 PM
Subject: non-SCSI disks on a SCSI disk interface (was Re: Space, the next
frontier)

...
 ard(a)p850ug1.demon.co.uk (Tony Duell) wrote:
  Most later workstations had SCSI interfaces for
the hard disk (even if
 they then broke that by insisting on an ST506 drive on the other side of
 a SCSI->ST506 interface, as ICL and Torch both did). Some older 
Sun did this too.  It wasn't 'til SunOS 4.0 that the SCSI-disk driver
would actually talk to SCSI disks.  Before that, it wanted to talk to
an Adaptec ACB4000 or an Emulex MD21 (for ESDI disks).

I think I remember reading somewhere that this was done because the
SCSI-to-whatever interface had the intelligence for bad-block
remapping.  But I wouldn't be surprised to find that the cost of the
drives had something to do with it; I remember Amiga folks scheming to
use ACB4000 boards with their SCSI interfaces because it was cheaper
than buying a SCSI disk, and I've opened a few Mac SCSI hard disk
boxes to find the same sort of thing inside.

-Frank McConnell